If you miss the last combi to Villahermosa [1], stay the night at Hotel Plaza Broca (Blvd. Adolfo López Mateos at Nicolas Bravo, tel. 933/334-4060, US$23.25 s, US$26–32.50 d). It offers simple but very clean rooms in the heart of town; all have air-conditioning, cable TV, telephone, and 24-hour hot water. With a private parking garage, this is one of the best deals around. Ask for a room in back, as the road in front can get loud.
Taco and hotdog stands rule in this town. While not the healthiest of options, these will definitely keep your belly full for the night. Look for them around the central plaza, just half a block from the combi station.
Links:
[1] http://www.moon.com/destinations/cancun-the-yucatan/the-state-tabasco/villahermosa